The invention relates to a method for operating a book forming and pressing machine which essentially consists of a re-forming device, a pressing device, and a loading device, wherein the loading device essentially is formed by a loading table and wherein the pressing device consists of a number of spaced-apart pressing plates and burn-in rails. The re-forming device is provided with a forming tool to shape or form the front cut on a book block, wherein the pressing device is operated with at least one station for accommodating a book block, and wherein the forming tool executes a series of movements in a plane or in space to form the front cut.
Known book forming and pressing machines are used in known book production lines for one of the last finishing steps in book production, meaning for the re-forming of a book block that has already been combined with a book cover.
A book forming and pressing machine is disclosed in German patent document DE 4422783 A1, which machine comprises a number of pressing devices with thereon arranged joint-burn-in devices, positioned on a rotor which is driven intermittently around a vertical axis of rotation. The books, which are supplied to a feed-in station of a pressing device that completely accommodates the books, are formed continuously via burn-in rail and are held by the same pressing plate until they are discharged at the discharge station. Between the feeding of the book blocks encased in covers and the discharge of the formed and pressed books, the rotor executes several intermittent rotational movements which are utilized as intervals for the pressing and/or burn-in operations.
The German patent document DE 19741755 A1 also discloses a method for setting up a book binding machine, comprising processing stations with servo components which are arranged along the material flow. The problem defined for this document is that the servo components are adjusted with computer control on the basis of specified adjustment variables. With respect to an improvement in the product quality and a shortening of the setup times, the document discloses that the results of individual functions of the process are determined with the aid of data recorders as actual values for a finished product and the resulting variables are then transmitted to a control computer for comparison. Empirical values stored in the control computer are used for adjusting the servo components, wherein the actual value of the finished product is compared in the control computer with the desired value for the finished product, taking into consideration an actual value for the fed-in product which is known to the station and is compared to the empirical values. In case of a deviation from the desired value, the servo components are automatically readjusted. However, one skilled in the art cannot find anywhere in the complete document a teaching describing the steps for a technical action because each operation for a book production is carried significantly by so-called empirical values which are stored in the control computer. This document consequently does not offer instructions to one skilled in the art for recreating the method.
Book forming and pressing machines which are known per se thus feed a book with the aid of a loading device into a pressing device and between two pressing plates. The books consist of book blocks encased in book covers and for the most part have a rounded book block back, with the front cut arranged opposite the back. The book block is positioned with its back resting on a loading table in the book forming and pressing machine and is subjected to a re-forming operation. In the process, joints are formed in the book, using burning rails, while the book is positioned in the book forming and pressing machine. The books are held in place between the pressing plates until they are discharged from the book forming and pressing machine.
A known re-forming device used for the re-forming operation is provided with a vertically adjustable forming tool, also called a loading punch or a die, which can be lowered onto the front cut. If the burn-in rails are closed only slightly and no pressure or only a slight pressure is exerted with the pressing plates onto the cased-in book block, the book block can be pressed into the back of the cover by lowering the forming tool against the front cut. The back insert and the flyleaf, as well as the two book cover sections, are pressed in a joint against the forming rails, so as to form a joint. With this method, it is important for the quality of the produced books that the forming tool faces the front cut and that its form matches the format of the book to be created.
With industrial book production lines, continuously changing book formats and small editions, up to the production of a single book, not only require frequent replacement of these forming tools but also require frequent replacements and more comprehensive adaptations of the book forming and pressing machine on the whole.
With the known methods and machines, the loading height for the book is individually adjusted during the loading of a book into the book forming and pressing machine, using a visual inspection, since the form of the book back and the thickness of the back insert influence the position of the book on the loading table, meaning the loading height must be changed.
Following the loading operation, a machine operator must take care to ensure that the forming edge has been positioned in a region for the burn-in rail and that the tools which must be replaced in the book forming and pressing machines have been selected to match the form of the book. According to the prior art, these forming tools are adjusted by sight.
A method of this type no longer meets the current order situation for an industrial book production line.